title: The wild boar (Sus scrofa Linnaeus, 1758) as secondary reservoir of Fasciola hepatica in Galicia (NW Spain).
abstract: Fasciolosis is an emerging or reemerging human and animal disease in numerous parts of the world. In Galicia (NW, Spain), the wild boar (Sus scrofa) is the main wild ungulate in terms of abundance and distribution. Its population has continuously increased over the past decades and this population growth has been accompanied by a reduction of habitats, so that the wild boar populations encroach more and more frequently onto agricultural lands. The increase of the interface area between livestock and the wild boars frequently involves the sharing of pastures and water sources, so that the circulation of common pathogens is propitiated. This is the first report concerning the importance of the wild boar as a possible reservoir of Fasciola hepatica infection in Spain. Livers from 358 hunted wild boars were analyzed showing that 11.2% were parasitized by F. hepatica, with burdens ranging from 1 to 14 flukes (mean=2.3). Fecal analysis demonstrated that 40.0% of parasitized animals shed F. hepatica eggs with a mean excretion of 6.1 eggs per gram of feces (epg). The presence of coproantigens analyzed by MM3-COPRO ELISA was positive in 62.9% of infected wild boars. After incubation, the percentage of hatched eggs ranged between 41.0% and 90.0% suggesting that the wild boar is very likely to contribute to the environmental contamination with viable parasite eggs. Comparative morphometric data were obtained using a computer image analysis system (CIAS) on the basis of standardized measurements. F. hepatica from cattle, sheep and wild boars from the same geographical area presents a similar body development and gravidity. Our study shows for the first time that the F. hepatica uterus from the wild boar presents an intermediate size between that found in primary reservoir hosts such as cattle and sheep, i.e., the individual potential egg output capacity of the wild boar does not greatly differ from that detected in Galician livestock. These results show that F. hepatica in Galicia has a normal development in wild boars, presenting its own characteristics in shape and size in comparison with other host species. The high prevalence of infection detected in the wild boar, the normal fluke development in the liver, and the possibility of shedding F. hepatica eggs capable of embryonating and giving rise to viable miracidia with the potential to infect intermediate hosts suggest a possible role of this species as a secondary reservoir in this Spanish region.
authors.affiliation: Laboratorio de Parasitología, Centro de Investigaciones Agrarias de Mabegondo, Instituto Galego da Calidade Alimentaria-Xunta de Galicia, Carretera AC-542 de Betanzos a Mesón do Vento, Km 7, 15318 Abegondo, A Coruña, Spain. Electronic address: mercedes.mezo.menendez@xunta.es.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Mezo
authors.forename: Marta
authors.initials: M
authors.lastname: González-Warleta
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Castro-Hermida
authors.forename: M Yolanda
authors.initials: MY
authors.lastname: Manga-González
authors.forename: Raquel
authors.initials: R
authors.lastname: Peixoto
authors.forename: Santiago
authors.initials: S
authors.lastname: Mas-Coma
authors.forename: M Adela
authors.initials: MA
authors.lastname: Valero
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000032:analysis; D004197:Disease Reservoirs / Q000662:veterinary*; D005210:Fasciola hepatica / Q000502:physiology*; D005211:Fascioliasis / Q000453:epidemiology / Q000662:veterinary*; D005243:Feces / Q000469:parasitology; D008099:Liver / Q000469:parasitology; D015995:Prevalence; D013030:Spain; D034421:Sus scrofa; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology / Q000469:parasitology
chemical_list: D000953:Antigens, Protozoan
keywords: Cattle; Fasciola hepatica; Galicia (Spain); Secondary reservoir; Sheep; Wild boar